Featured Research

from universities, journals, and other organizations

Urban underground holds sustainable energy

Date:
October 28, 2013
Source:
Karlsruhe Institute of Technology
Summary:
Vast energy sources are slumbering below big cities. Sustainable energies for heating in winter and cooling in summer may be extracted from heated groundwater aquifers. Researchers developed an analytical heat flux model and found that increasing heat in the underground is mainly caused by an increase in surface temperatures and heat release from buildings.

Vast energy sources are slumbering below big cities. Sustainable energies for heating in winter and cooling in summer may be extracted from heated groundwater aquifers. Researchers from KIT and ETH Zurich developed an analytical heat flux model and found that increasing heat in the underground is mainly caused by an increase in surface temperatures and heat release from buildings. Work of the scientists is now reported in the journal Environmental Science and Technology.

Temperatures in big cities are far above those in the surrounding rural area: Dense settlement, surface sealing, industry, traffic, and lacking vegetation cause an urban microclimate with increased tem-peratures in the atmosphere. Temperature anomalies also develop in the underground. They spread laterally and vertically. In the past decades, groundwater in conurbations heated up considerably. "In Karlsruhe, the average heat flux density into subsurface aquifers was 759 milliwatts per square meter in 1977. In 2011, a heat flux density of 828 milliwatts per square meter was reached," says Junior Professor Philipp Blum, Head of the Engineering Geology Division of the KIT Institute of Applied Geosciences (AGW). "This amount of heat corresponds to 1 petajoule per year and would suffice to supply at least 18,000 households in Karlsruhe with heat."

In cooperation with Kathrin Menberg and Axel Schaffitel from KIT and Dr. Peter Bayer from ETH Zurich, Philipp Blum also studied the origin of heat in the underground of conurbations. The scientists developed an analytical heat flux model to examine factors, such as the increase in temperatures of sealed surfaces, heat release from buildings, sewage ducts, and underground district heating networks as well as discharge of thermal waste water. By modeling anthropo-genic heat fluxes into the underground of the city of Karlsruhe, the researchers determined long-term trends of heat flux processes. They found that the increased surface temperature and heat release from buildings in particular are responsible for the increase in tem-peratures in the subsurface area.

The energy from close-to-surface groundwater aquifers might be used for heating in winter and cooling in summer via geothermal heat pumps and groundwater heat pumps. Use of this geothermal potential would not only cover part of the growing demand for ener-gy, but also reduce the emission of greenhouse gases, which would counteract heating of the cities.


Story Source:

The above story is based on materials provided by Karlsruhe Institute of Technology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kathrin Menberg, Philipp Blum, Axel Schaffitel, Peter Bayer. Long-Term Evolution of Anthropogenic Heat Fluxes into a Subsurface Urban Heat Island. Environmental Science & Technology, 2013; 47 (17): 9747 DOI: 10.1021/es401546u

Cite This Page:

Karlsruhe Institute of Technology. "Urban underground holds sustainable energy." ScienceDaily. ScienceDaily, 28 October 2013. <www.sciencedaily.com/releases/2013/10/131028090414.htm>.
Karlsruhe Institute of Technology. (2013, October 28). Urban underground holds sustainable energy. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2013/10/131028090414.htm
Karlsruhe Institute of Technology. "Urban underground holds sustainable energy." ScienceDaily. www.sciencedaily.com/releases/2013/10/131028090414.htm (accessed April 23, 2014).

Share This



More Matter & Energy News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Air Force: $4.2B Saved from Grounding A-10s

Air Force: $4.2B Saved from Grounding A-10s

AP (Apr. 23, 2014) Speaking about the future of the United States Air Force, Chief of Staff Gen. Mark Welsh says the choice to divest the A-10 fleet was logical and least impactful. (April 23) Video provided by AP
Powered by NewsLook.com
Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com
China Falls for 4x4s at Beijing Auto Show

China Falls for 4x4s at Beijing Auto Show

AFP (Apr. 22, 2014) The urban 4x4 is the latest must-have for Chinese drivers, whose conversion to the cult of the SUV is the talking point of this year's Beijing auto show. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins